Small Genus Research Articles

Phylogenomic insights into species relationships, reticulate evolution, and biogeographic diversification of the ginseng genus Panax (Araliaceae), with an emphasis on the diversification in the Himalayan‐Hengduan Mountains

AbstractPanax (Araliaceae) is a small genus containing several well known medicinally important species. It has a disjunct distribution between Eastern Asia and Eastern North America, with most species from eastern Asia, especially the Himalayan‐Hengduan Mountains (HHM). This study used the genomic target enrichment method to obtain 358 nuclear ortholog loci and complete plastome sequences from 59 accessions representing all 18 species of the genus. Divergence time estimation and biogeographic analyses suggest that Panax was probably widely distributed from North America to Asia during the middle Eocene. During the late Eocene to Oligocene Panax may have experienced extensive extinctions during global climate cooling. It survived and diverged early in the mountains of Southwest China and tropical Indochina, where some taxa migrated northwestward to the HHM, eastward to central and eastern China, and then onward toward Japan and North America. Gene flow is identified as the main contributor to phylogenetic discordance (33.46%) within Panax. We hypothesize that the common ancestors of the medicinally important P. ginseng + P. japonicus + P. quinquefolius clade had experienced allopolyploidization, which increased adaptability to cooler and drier environments. During the middle to late Miocene, several dispersals occurred from the region of the HHM to contiguous areas, suggesting that HHM acted as a refugium and also served as a secondary diversification center for Panax. Our findings highlight that the interplay of orographic uplift and climatic changes in the HHM greatly contributed to the species diversity of Panax.

Comparative Analyses of the Complete Mitogenomes of Two Oxyria Species (Polygonaceae) Provide Insights into Understanding the Mitogenome Evolution Within the Family

Oxyria (Polygonaceae) is a small genus only comprising two species, Oxyria digyna and O. sinensis. Both species have well-documented usage in Chinese herbal medicine. We sequenced and assembled the complete mitogenomes of these two species and conducted a comparative analysis of the mitogenomes within Polygonaceae. Both O. digyna and O. sinensis displayed distinctive multi-branched conformations, consisting of one linear and one circular molecule. These two species shared similar gene compositions and exhibited distinct codon preferences, with mononucleotides as the most abundant type of simple sequence repeats. In the mitogenome of O. sinensis, a pair of long forward repeat sequences can mediate the division of molecule 1 into two sub-genomic circular molecules. Homologous sequence analysis revealed the occurrence of gene transfer between the chloroplast and mitochondrial genomes within Oxyria species. Additionally, a substantial number of homologous collinear blocks with varied arrangements were observed across different Polygonaceae species. Phylogenetic analysis suggested that mitogenome genes can serve as reliable markers for constructing phylogenetic relationships within Polygonaceae. Comparative analysis of eight species revealed Polygonaceae mitogenomes exhibited variability in gene presence, and most protein-coding genes (PCGs) have undergone negative selection. Overall, our study provided a comprehensive overview of the structural, functional, and evolutionary characteristics of the Polygonaceae mitogenomes.

Four New Species of Deconica (Strophariaceae, Agaricales) from Subtropical Regions of China

Deconica is a relatively small genus, with only 90 names recorded in previous research. In this study, four new species of Deconica have been identified based on morphological and phylogenetic evidence from subtropical regions of China. This represents the first discovery of new species of Deconica in China. Morphologically, D. austrosinensis is characterized by medium-sized spores that are elliptical to elongated-ellipsoid in face view, and fusiform to sublageniform and slightly thick-walled pleurocystidia; D. furfuracea is identified by a well-developed and evanescent veil, medium-sized spores that are rhomboid to mitriform in face view, and fusiform to subclavate pleurocystidia that are rare and subacute at apex; D. fuscobrunnea is recognized by dark brown pileus, medium-sized spores that are rhomboid to mitriform in face view, an ixocutis pileipellis, lageniform cheilocystidia with a long neck and lacks pleurocystidia; D. ovispora is distinguished from other Deconica species by medium-sized spores that are ovoid in face view, an ixocutis pileipellis, lageniform cheilocystidia with a long to short neck, and lacks pleurocystidia. Their distinct taxonomic status is confirmed by the positions of the four new species in ITS + LSU phylogenetic trees. Detailed descriptions and morphological photographs of four new species are presented.

SesamumGDB: a comprehensive platform for Sesamum genetics and genomics analysis.

Sesame (Sesamum indicum L., 2n = 26) is a crucial oilseed crop cultivated worldwide. The ancient evolutionary position of the Sesamum genus highlights its value for genomics and molecular genetics research among the angiosperms of other genera. However, Sesamum is considered a small orphan genus with only a few genomic databases for cultivated sesame to date. The urgent need to construct comprehensive, curated genome databases that include genus-specific gene resources for both cultivated and wild Sesamum species is being recognized. In response, we developed Sesamum Genomics Database (SesamumGDB), a user-friendly genomic database that integrates extensive genomic resources from two cultivated sesame varieties (S. indicum) and seven wild Sesamum species, covering all three chromosome groups (2n = 26, 32, and 64). This database showcases a total of 352 471 genes, including 6026 related to lipid metabolism and 17 625 transcription factors within Sesamum. Equipped with an array of bioinformatics tools such as BLAST (basic local alignment search tool) and JBrowse (the Javascript browser), SesamumGDB facilitates data downloading, screening, visualization, and analysis. As the first centralized Sesamum genome database, SesamumGDB offers extensive insights into the genomics and genetics of sesame, potentially enhancing the molecular breeding of sesame and other oilseed crops in the future. Database URL: http://www.sgbdb.com/sgdb/.

Revision of the Chinese termite genus Peribulbitermes (Blattodea, Isoptera, Termitidae): A new synonym of Ahmaditermes

The genus Peribulbitermes is a small genus in Nasutitermitinae comprising three species distributed only in China. Type specimens of Peribulbitermes dinghuensis Li, 1985 and Peribulbitermes jinghongensis Li, 1985 are obtained in our study. After examining the morphological characters of the specimens, it is found that P. jinghongensis cannot be differentiated from P. dinghuensis by the diagnostic characters reported in original description. We propose that P. jinghongensis is the junior synonym of P. dinghuensis. Additionally, molecular phylogenetic relationships of Peribulbitermes, with its morphologically similar genera, Bulbitermes, Ahmaditermes and Nasutitermes, as well as other nine genera in Nasutitermes Group of Nasutitermitinae were analysed based on mitochondrial COI, COII and 16S rRNA genes. The results show that the relationship between Peribulbitermes and Ahmaditermes is the closest. Peribulbitermes should be downgraded to synonymy of Ahmaditermes. P. dinghuensis and Peribulbitermes parafulvus (Tsai and Chen, 1963) should be transferred to Ahmaditermes as Ahmaditermes dinghuensis and Ahmaditermes parafulvus.

An integrative taxonomic study of the genus Lethocolea (Marchantiophyta: Acrobolbaceae)

Background and aims – Lethocolea (Acrobolbaceae) is a small liverwort genus of seven species distributed in temperate regions of the Southern Hemisphere and on tropical mountains. The taxonomic history of the genus has been chaotic, the species were described under many different names and have been distinguished mainly based on geography. Here, we undertook a taxonomic revision of the genus based on a reassessment of morphological characters and a molecular analysis. Material and methods – Type material and additional collections from 17 herbaria were examined in the morphological study. Sequences of the rps4 chloroplast region and maximum likelihood analyses were used to reconstruct the phylogeny. Key results and conclusions – Two fully supported clades were resolved within Lethocolea lending support to the recognition of two subgenera, subgen. Lethocolea and subgen. Symphyomitra. Lethocolea congesta from Africa, and L. glossophylla and L. radicosa from America exhibited considerable morphological overlap and were not distinguishable based on rps4 sequences. The latter two species are reduced into synonymy with L. congesta, whose range spans across Africa, the Neotropics and southern South America. In Australasia, where only one species, L. pansa, is recognized, two morphotypes were found. The first one, with a smooth cuticle, wingless gemmae, and leaf cells without trigones, is identical to the type of L. pansa and occurs in Australia and New Zealand. In addition, the species is newly reported from South Africa. The second morphotype has a papillose cuticle, winged gemmae, and leaf cells with distinct trigones, and is assigned to L. javanica, which ranges across Australasia and furthermore occurs in Java and India. The recognition of these two species is supported by molecular analysis. Altogether, we recognize four species within Lethocolea, which are thoroughly described, illustrated, and keyed. We present 12 new lectotypifications.

Description of a new species of potter wasp (Hymenoptera, Vespidae, Eumeninae) from Northeast India

Pseumenes Giordani Soika, 1935 is a small genus of potter wasps occurring in Oriental, Australian and Palearctic Regions. Only one species, Pseumenes depressus (de Saussure, 1855) is known so far from India. A new species, Pseumenes siangensis sp. nov. from Arunachal Pradesh, is described. The morphological affinities of the new species are discussed. The new species is compared with the closely related P. depressus as well as P. laboriosus. Since P. depressus is similar to P. laboriosus, comparisons were made between P. laboriosus and P. siangensis sp. nov. The apical teeth of the propodeum are medium sized and blunt in P. siangensis sp. nov. (long and sharp in P. laboriosus); the posterior part of the first tergite is densely punctate in the middle P. siangensis sp. nov. (almost impunctate in P. laboriosus). The clypeus without a median black spot in P. siangensis sp. nov. (with median black spot in P. laboriosus).

TWO NEW SPECIES OF PAYPAYROLA (VIOLACEAE) FROM THE CAMPINARANAS OF THE BRAZILIAN AMAZON

Paypayrola is a small genus of Violaceae consisting of small trees or shrubs found in the humid forests of South America. The boundaries between species have proven problematic, particularly among taxa in the Amazon. Through the analysis of Paypayrola specimens from this region, we have identified two new species, potentially restricted to campinarana vegetation. Paypayrola oppositifolia and P. pubiflora are distinguished from other known species in the genus by their phyllotaxy and the indumentum of reproductive parts. We provide morphological descriptions, illustrations, distribution maps, conservation status of the new species, and compare them with Amazonian species that are morphologically similar.

The fourth species of Sinamma Lin & Li, 2014 (Araneae, Tetrablemmidae) from China.

Sinamma Lin & Li, 2014 is a small tetrablemmid genus distributed in China, with three currently known species: Sinammaoxycera Lin & Li, 2014 from Guangxi Zhuang Autonomous Region and S.quadrata Tong & Li, 2022 and S.yingae Tong & Li, 2022 from Guangdong Province. While examining spider specimens obtained by sifting leaf litter from Danxiashan National Nature Reserve in Guangdong Province of China, we discovered a new species of the genus Sinamma, S.danxia sp. nov., which is described here.

One becomes three: An integrative morphological and molecular analysis of the windowpane oyster Placuna (Bivalvia: Pectinida) reveals new species.

For decades, many marine animals have been considered to exhibit cosmopolitan or transoceanic distribution. This situation is prevalent in Asia, where many species were collected and named by American or European experts in the 1700s to early 1900s. Using the windowpane oysters Placuna-a small genus of bivalves with five recognized species-we show that careful analysis is required to reassess the validity of these species. Currently, only two species of Placuna (P. placenta and P. ephippium) widely reported in the Indo-Pacific region have been recorded from Chinese coastal waters. Here, we described two new species of Placuna from China. Placuna vitream sp. nov. can be distinguished from P. placenta by its larger ridge angle. Phylogenetic analysis using five gene fragments fully supported that P. vitream sp. nov. is a sister to the specimen from Singapore identified as P. placenta and more distant from other Placuna species with available molecular data. Besides, based on subfossil shells, we describe Placuna aestuaria sp. nov. that differs from its congeneric species by its broad hinge, medium ridge angle, and nearly straight ridges. Finally, we suggest a combination of hinge structure and ridge angle that can be used for identifying Placuna species and preparing a key to this genus. Our findings of two new species expand the diversity of Placuna and prompt reassessment of the many presumably widely distributed marine species in Asia.

Phylogenetic positions of Thai members of Gymnema, Gymnemopsis and Sarcolobus (Apocynaceae, Asclepiadoideae, Marsdenieae), and two new Sarcolobus species uncovered by morpho-molecular evidence.

The present study assesses the phylogenetic position of certain Thai members of Gymnema, Gymnemopsis, and Sarcolobus in relation to other known Marsdenieae species. Fifteen accessions newly sequenced from Thailand were added to the dataset of the homologous sequences of 125 accessions of Marsdenieae downloaded from GenBank. In our molecular phylogeny, almost all the delimited major clades and their relationships are largely congruent with those revealed in previous studies. The monophyly of Gymnema (including the former Jasminanthes species) and that of Sarcolobus, as presently circumscribed, are confirmed. The new accessions of these two genera from Thailand are well grouped with the members of their respective genera. Our analyses provide the first molecular evidence for recognition of Gymnemopsis, a small Asian genus that has never been included in the previous phylogenetic studies, as a distinct genus. All elements of Gymnemopsis are retrieved as a well-supported monophyletic group that is strongly supported as sister to Lygisma, another small Asian genus that most closely resembles it in growth habit, color of latex, indumentum on plant parts, corona structure and follicle traits. Combined molecular phylogenetic, morphological and ecological data also support recognition of two new Sarcolobus species from Thailand, Sarcolobus busbanianus sp. nov. and S. flavus sp. nov. Similarities and differences between these new species and their close relative, S. carinatus, are discussed. In addition, this study also reveals the first record for Thailand of Gymnema lacei. Keys to the species of Gymnemopsis (for all members of the genus), Gymnema and Sarcolobus (for Thai members of these genera) are provided.

Phylogeny, niche modelling and morphology unveil a new lianescent species of Sigmoidotropis (Leguminosae, Papilionoideae) across rainforest enclaves within Brazilian dry vegetation

AbstractThe small Neotropical papilionoid legume genus Sigmoidotropis (nine species) has been described only relatively recently as the result of the taxonomic rearrangement of the genus Vigna (subtribe Phaseolinae), based on phylogenetic analyses of DNA sequence data. Here, we formally propose a new lianescent species of Sigmoidotropis that occurs disjunctly in enclaves of moist forest of mountainous regions surrounded by dry vegetation at three different localities in the Brazilian states of Bahia and Minas Gerais. Its phylogenetic position and morphological affinities with other genera of Phaseolinae were evaluated by Bayesian inference and maximum likelihood analyses, using sequence data from the nuclear ITS/5.8S and plastid trnK/matK. To better understand this new species’ widely disjunct distribution and a possible connection between its populations in the past, an environmental niche modelling (ENM) analysis was performed. The phylogenetic analyses revealed that Sigmoidotropis appears closest to the genera Ancistrotropis and Delgadoana, together forming the Sigmoid‐keel clade. The new species proposed here is strongly recovered within Sigmoidotropis, being most closely related to S. ekmaniana, S. elegans, and S. megatyla. The ENM indicated changes in the potential distribution of the new species over different climatic periods, with expansion during colder periods and contraction during warmer periods, leading to possible relictual populations in moist forest enclaves. A description of the new species Sigmoidotropis maculata is presented, along with illustrations, a distribution map, taxonomic comments, and conservation status assessment.

Recent fieldwork and fungarium studies double known diversity of Chlorosplenium and improve understanding of species distributions

ABSTRACT Chlorosplenium is a small genus comprising five species of inoperculate discomycetes in the order Helotiales (Leotiomycetes) often recognizable by their bright yellowish-green colors and gregarious growth on wood. In this study, we describe five new species—C. aotearoa, C. australiense, C. cusucoense, C. epimorsicum, and C. hawaiiense—based on a combination of recent fieldwork and examination of previously collected fungarium specimens. We use an integrative taxonomic approach to support the distinction of new species, incorporating morphology and DNA sequence data with biogeography. Macro- and micromorphological features of apothecia for all species and culture characteristics for four of the five new species are documented. A multilocus phylogeny based on nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2, partial large subunit nuc ribosomal DNA (28S nuc rDNA), and A–B regions of the largest subunit of RNA polymerase II (RPB1) gene is presented. Additionally, we report Chlorosplenium chlora from Europe for the first time and expand our knowledge of the diversity and distributions of species in this genus in America, Australia, and New Zealand.

Micropropagation and genetic transformation of Byblis liniflora

AbstractByblis, a small genus of carnivorous plants predominantly found in Australia, is characterized by its passive trapping mechanism and unique floral features. The chemical composition of Byblis, including identified phenylethanoid glycosides, particularly acteoside, highlights its pharmacological potential with various biological activities. In vitro culture techniques have been established for propagation, with micropropagation protocols developed for different Byblis species. However, information on genetic transformation, vital for trait modification and enhanced pharmacological interest, remains limited. This study focuses on optimizing micropropagation, adventitious regeneration, and genetic transformation methods for Byblis liniflora. Adventitious regeneration rates were highest in medium with reduced Murashige and Skoog salts (MS/10) and sucrose (3 gL−1) concentrations. Zeatin supplementation (1 mgL−1) further improved regeneration rates and bud development with 100% of regenerated root explants and 8.8 shoots per explant. Liquid MB3 medium supplemented with indole-3-acetic acid (IAA) 5 mgL−1 facilitated efficient rooting and acclimatization. The establishment of an efficient Rhizobium-mediated genetic transformation method yielded transgenic plants expressing green fluorescent protein (GFP). Molecular analysis confirmed transgene integration, marking the first successful genetic transformation in the Byblis genus. These advancements pave the way for exploring gene function and enhancing pharmacological properties, thereby broadening our understanding and utilization of carnivorous plants like Byblis.

Elachanthus, Isoetopsis and Kippistia are nested in the genus Minuria (Asteraceae: Astereae)

While conducting phylogenetic analyses of sequence-capture data of Australian members of Asteraceae tribe Astereae, we found that Elachanthus pusillus F.Muell., Isoetopsis graminifolia Turcz. and Kippistia suaedifolia F.Muell. formed a clade with Minuria. We, therefore, conducted an analysis focused on this clade, but with replicate samples of the three smaller genera, and confirmed our results. Kippistia had been synonymised under Minuria between 1876 and 1980, when it was reinstated. Elachanthus and Isoetopsis had not previously been suggested to be part of Minuria, and, indeed, Isoetopsis had been considered so morphologically divergent that even its tribal affiliations were long controversial. However, on closer examination, Elachanthus and Isoetopsis are strikingly similar to Minuria, especially in cypsela and pappus morphology. The evolution of both genera from a common ancestor in Minuria appears plausible in the light of their overall similarity to annual species of that genus such as M. annua, their multiple uniform rows of herbaceous phyllaries with scarious margins, a pappus of scales v. the tendency of Minuria to form pappi with scale-like bases, female outer and male inner florets, and a cypsela indumentum shared with some species of Minuria. We propose the following three new combinations under Minuria: M. pusilla, M. glabra and M. graminifolia.

First record of the genus Dolichosoma Stephens (Coleoptera, Dasytidae) from China, with two newly-recorded species.

Dolichosoma Stephens, 1830 is small genus belonging to the tribe Dasytini of the family Dasytidae (Coleoptera, Cleroidea), with two subgenera and five species hitherto known. It is widespread in the Palearctic Region of Eurasia, but has never been reported from China until now. The genus Dolichosoma Stephens, 1830 is reported from China for the first time, with discoveries of two newly-recorded species, including D. (Dolichomorphus) femorale Morawitz, 1861 and D. (Dolichosoma) lineare (Rossi, 1794) from Xinjiang Autonomous Region. They are re-described in detail and illustrated with habitus, ultimate abdominal tergites and sternites and genitalia of both sexes, as well as tarsal claws of male. In addition, a macrohabitat photograph and a distribution map of the two species occurring in China are provided.

An integrative taxonomy of Asian Caryodaphnopsis (Lauraceae) based on morphology and phylogenomics

AbstractCaryodaphnopsis is a small genus of the Lauraceae family with disjunct distribution in tropical Asia and tropical America. Taxa from each region form a well­supported monophyletic clade. However, the species circumscription in Asian Caryodaphnopsis remains ambiguous due to few and generally unstable morphological characters used for classification. To address this, we conducted an integrative taxonomy of the Asian clade. We investigated 13 populations, sampled 57 accessions covering the entire taxonomic diversity, geographic range, and morphological variation in Asia, and reconstructed a new phylogeny using single‐nucleotide polymorphisms. We obtained a well‐resolved phylogeny of the Asian Caryodaphnopsis. The first diverged clade consists of three species endemic to lowland forests. The second (largest) clade (eight species in total) mainly occurs in limestone mountain forests and has a double‐layered lower leaf epidermis morphology of type 2 (less complete roomy with closed “roof”) and type 3 (complete roomy with closed “roof”). Based on the diagnostic morphological characters, distinct distributional ranges, and monophyly of each clade, we recognize 12 species in the Asian Caryodaphnopsis, including three new species: C. cangyuanensis sp. nov., C. hekouensis sp. nov., and C. rubrinervis sp. nov. We also reinstate C. latifolia, and re‐circumscribe the widespread C. tonkinensis and other species based on fruit and inflorescence morphology and molecular evidence.

The essential oil chemical composition of a sicilian (Italy) accession of Doronicum caucasicum M. Bieb

Doronicum is a relatively small genus belonging to the tribe Senecioneae (Fam. Asteraceae), distributed in Asia, Europe, and North Africa. Some of its species are considered toxic due to the presence of pyrrolizidine alkaloids whereas some other ones are largely utilised in the ethnopharmacology of several countries. In the present study, the essential oil composition of a Sicilian accession of Doronicum caucasicum M. Bieb (syn. D. orientale Hoffm.), not previously investigated, is particularly rich in sesquiterpene hydrocarbons (80.3%) with germacrene D (58.9%), α-humulene (8.8%), and β-caryophyllene (6.5%) as main metabolites. A comparison with all the essential oils from Doronicum taxa studied so far has been carried out.

Three new species, one subspecies, and new records of the Oriental genus Loeblites Franz (Coleoptera: Staphylinidae: Scydmaeninae)

Loeblites is a small genus of Oriental Scydmaeninae, currently comprising only five species distributed in Thailand, Malaysia (Sabah), China (Yunnan), and the Philippines (Mindanao). Loeblites anaiensis sp. n. (Sumatra), L. umphangensis sp. n. (Thailand), L. pseudominor pseudominor sp. n. (Borneo, Thailand), and L. pseudominor sumatrensis subsp. n. (Sumatra) are described. New records for L. sabahensis Franz in Sarawak are reported, a species so far known to occur only in Sabah. Identification key to species of Loeblites is given.

The chemical composition of the essential oil of Calendula suffruticosa subsp. fulgida (Raf.) Guadagno aerial parts growing wild in Sicily (Italy)

Calendula L. is a relatively small genus belonging to the Asteraceae family, distributed in Europe to Western Himalaya, Macaronesia, Mediterranean to Sahara and Arabian Peninsula. Some of its species are largely utilised in the ethnopharmacology of several countries and several documented biological properties have been determined. In the present study, the essential oil composition of Calendula suffruticosa subsp. fulgida (Raf.) Guadagno, collected in Sicily, a plant never previously investigated, has been carried out. The oil was shown to be quite rich in sesquiterpene hydrocarbons (44.5%) with δ-cadinene (15.9%) and viridiflorene (6.3%) as main metabolites. Also, monoterpene hydrocarbons (39.3%) were present in good amount being α-thujene (10.0%) and sabinene (6.9%) the principal metabolites of the class. The comparison with all the essential oils from Calendula taxa studied so far has been carried out.